1. Field of the Invention
The present invention relates to a fan apparatus having a stator blade.
2. Description of Related Art
In recent years, as the capacities of electronic equipment are enhanced, the amount of heat emitted by internal components of the electronic equipment is increased. In order to control the increase in the temperature inside the electronic equipment, a fan apparatus is used.
There are mainly two types of functions of the fan apparatus. They are: (a) to discharge heated air within the electronic component out of a housing accommodating the electronic component, and (b) to provide cool air directly to the heat emitting component within the electronic equipment in order to reduce the temperature of the electronic component. In order to achieve the function (a) above, the fan apparatus is required to have high air flow rate and high static pressure, and to achieve the function (b), efficiency in wind speed distribution is required beside the high air flow rate and high static pressure. Hereinafter, what is meant by the wind speed distribution is a characteristic which defines a distribution of air flow discharged from an air outlet of the fan apparatus. Note that a degree of quietness is also an important element for both functions (a) and (b).
According to a fan apparatus in general, when an air flow is discharged from the air outlet, the air flow spreads, due to centrifugal force of the rotation of an impeller, in a radial direction with respect to the impeller. However, it is important that the air flow is directed at portions which emit heat in order to increase the cooling efficiency of the fan apparatus.
In general, the fan apparatus includes the housing formed by using a mold for resin molding. Hereinafter, a general method for manufacturing the housing made by the resin molding will be described. The mold used for the resin molding includes a fixed mold portion and a sliding mold portion. When the fixed mold portion and the sliding mold portion are combined with one another, a space will be created therebetween having substantially the same shape as the shape of that which is formed by the mold. The sliding mold portion is slid toward the fixed mold portion, and resin is provided to the space created therebetween. After the resin is formed in accordance with the space between the sliding mold portion and the fixed mold portion, the resin is removed therefrom. As shown in FIG. 7, in a method as described above, when the sliding mold portion is removed from the fixed mold portion, the sliding mold portion is removed in a direction as indicated with an arrow A3. Therefore, an excessively bulging portion will be generated inevitably at a portion corresponding to an upper portion of an inclined portion 4a in the A3 direction. Although if a mold having a sliding portion which slides in an A1 direction shown in FIG. 7 is used, the problem concerning the excessively bulging portion 6 may be reduced, the cost for the manufacturing the housing will be increased, which may be problematic.
As described earlier, improving the efficiency of the air flow and the degree of quietness are critical for the fan apparatus having a stator blade.
Also, the excessively bulging portion generated due to the configuration of the housing including the stator blade is problematic in that the excessively bulging portion has an influence on the flow quantity of the air flow, distribution of the air flow and the degree of quietness of the fan apparatus. Therefore, it is critical how the influence of the excessively bulging portion is controlled.